Enzyme

Factors affecting enzymatic rate

1) Temperature

• increase temperature -> increase kinetic energy -> move faster and collide more
• if too high temperature -> denature -> break down bonding of enzyme -> change the active site -> can't bind with substrate longer
• Optinum temperature = highest temperature before denature

2) pH

• affect the charge of acidic side or basic side
• H+ break the hydrogen bond of the active site

3) Enzyme concentration

• reaction rate increase when the enzymatic concentration increase, as the chance of collision increase proportionally
• then its gradually slower since the limiting factor shifted to substrate concentration

4) Substrate concentration

• At low concentration, the active site are not all used.
• More substrate means more active site are occupied.
• then it reach the maximum where it is no more limiting factor

Industrial use

A) Advantages

1. speed up chemical reaction for mass production
2. specific in action, less likely to profuce undesirable product.
3. allow control rate by altering pH or temperature.

B) limitation

1. too sensitive to pH and temperature
2. the vessel have to be clean to prevent degeneration of enzyme

Inhibitor

A) Reversible:

Competitive inhibitor	Non-competitive inhibitor
similar to substrate	not necessary similar to substrate
inhibit by competing with substrate	inhibit by change the active site
bind the active site to block the substrate combine with the enzyme	bind the allosteric site of the enzyme to change the conformation of the active site
inhibitory effect related to the ratio of substrate and inhibitor	inhibitory effect is not related to the ratio of substrate and inhibitor

B) Inversible:

• inhibiting the enzymatic activity permently
• e.g: heavy metal

cofactor

• non-protein
• activate the inactive enzyme

Activators	Coenzyme	Prosthetic group
inorganic	organic	organic
metallic monovalent or divalent cation	lossely bonded	firmly bonded
	carrier from enzyme from enzyme	forming part of the active site
e.g Ca2+ for blood clotting Cl- for salivary amylas	e.g vitamin, NAD	e.g FAD,FADH